The present invention relates to a metallizing paste and a process for metallizing ceramic articles by using such a metallizing paste. More particularly, the invention relates to a paste to be used for depositing metallic layers on surfaces of ceramic articles and a process for depositing such metallic layers on the surfaces of the ceramic articles by using that paste. (2) Related Art Statement
Although ceramics have excellent properties such as high heat resistance, oxidation resistance, high hardness, etc., they have a shortcoming that they are relatively weak against mechanical and thermal shock due to their poor toughness. In order to compensate for the above shortcoming, a technique in which ceramic materials are used in combination with metallic materials is employed. For this purpose, as one of the techniques for combining ceramic materials with metals, there is known a process in which a layer of a high melting point metal such as metallic molybdenum or metallic tungsten is deposited onto a surface of a ceramic member (corresponding to a metallizing treatment in the present invention), and the ceramic member is bonded to a metallic member through the thus formed metallic layer. In order to deposit metallic layers onto ceramic articles, there is known a technique in which a mixed powder of metallic molybdenum and metallic manganese, or the like is applied onto the surface of a ceramic article and then the applied mixed powder is baked thereon (so-called high melting point metal depositing process or Telefunken process). However, with the recent increasing necessity of applying ceramic materials to mechanical parts, appearance of a metallizing paste giving rise to a greater bonding strength between a ceramic member and a metallic layer formed on the surface of the ceramic member has been earnestly desired. However, since the conventional metallizing pastes have been developed to metallize ceramic articles for semiconductor integrated circuits, ceramic members used in electronic circuit boards or electronic tube exterior devices, such metallizing pastes have defects that bonding strength between the metallic layers and the ceramic members are not necessarily sufficient.